Provided by: libalgorithm-checkdigits-perl_0.50-1_all #### NAME

```       CheckDigits::M07_001 - compute check digits modulo 7 method 1

```

#### SYNOPSIS

```         use Algorithm::CheckDigits;

\$m001 = CheckDigits('m001');

if (\$m001->is_valid('1234567892')) {
# do something
}

\$cn = \$m001->complete('123456789');    # \$cn = '1234567892'

\$cd = \$m001->checkdigit('1234567892'); # \$cd = '2'

\$bn = \$m001->basenumber('1234567892'); # \$bn = '123456789'

```

#### DESCRIPTION

```   ALGORITHM

2.  All digits at even positions are added.

3.  The sum of step 1 and 2 is taken modulo 7.

4.  This is the check digit.

METHODS
is_valid(\$number)
Returns true only if \$number consists solely of numbers and the last digit is a valid
check digit according to the algorithm given above.

Returns false otherwise,

complete(\$number)
The check digit for \$number is computed and concatenated to the end of \$number.

Returns the complete number with check digit or undef if \$number does not consist
solely of digits.

basenumber(\$number)
Returns the basenumber of \$number if \$number has a valid check digit.

Return undef otherwise.

checkdigit(\$number)
Returns the check digit belonging to \$number or undef if \$number does not consist
solely of digits.

EXPORT
None by default.

```

#### AUTHOR

```       Mathias Weidner, <mathias@weidner.in-bad-schmiedeberg.de>

```

#### SEEALSO

```       perl, www.pruefziffernberechnung.de.
```